The publication EP 0 793 460 B1 discloses an accommodative artificial lens implant employing optics that move in reaction to changes in the ciliary muscle. The intraocular lens arrangement used there is intended to be implantable in a human eye that comprises at least a section of a lens capsule, a ciliary muscle and zonules controlled by the ciliary muscle. By way of a special ring that is designed so as to cooperate with the ciliary muscle, linkage arms are formed, each of which is pivotably attached to the optic at a first position on the arm, and is fixed to the said ring at a second position on the arm. The linkage arms are intended to strengthen or enlarge the possible lens movements.
Adaptive lenses spaced apart from one another along the optical axis, in order to improve the accommodation capacity, are described for example in the U.S. Pat. No. 5,275,623. Specifically, the focussing there is achieved by shifting the lens axially in response to the normal contraction and expansion of the ciliary muscle. In the solution according to U.S. Pat. No. 5,275,623 the lens capsule remains present, but at least one additional lens is inserted. After subsequent closure the resulting hollow body, which in the exemplary embodiment mentioned there encloses two axially separated lenses, can be filled after lens implantation with a gas or liquid in order to separate the two lenses by a standard distance.
Such an implantation does not promise much success, because the lens capsule is practically impossible to close at present by surgical means. Hence the arrangement lacks a crucial element for conducting the muscular forces into the implant.
The state of the art as described above furthermore does not make possible any basic surgical adjustments that would allow the intraocular lens implant to be installed at precisely the correct distance from the retina, so as to enable the desired optimal long- and short-distance vision.
The document DE 689 02 614 T2 discloses an accommodating intraocular lens for the human eye that changes its light-refraction characteristics in response to movement of the eye muscle, so as to sharpen the focussing of objects that are at different distances, from the observer's point of view. In this regard a chamber filled with fluid under pressure is provided there, and a supporting vessel is needed to expand the lens capsule far enough to touch the ciliary body. A problematic aspect of the solution according to DE 689 02 614 T2 is the anchoring of the implant in the tender and sensitive lens capsule, which carries a corresponding risk that the capsule will be destroyed before, during or after the implantation.
In the case of the intraocular lens implant according to U.S. Pat. No. 6,217,612 B1 anchoring within the lens capsule is likewise necessary, with all the above-mentioned difficulties during the operation and postoperatively.
According to the teaching of U.S. Pat. No. 4,892,543 a fluid cushion is employed, which is pressed into a convex form by the contour of a rigid lens. This fluid cushion can either act on the ciliary muscle or be inserted into the lens capsule.
In the artificial lens arrangement according to U.S. Pat. No. 4,888,012 a fluid depot is inserted, which controls a lens formed by filling. The light refraction in this case is brought about by the optical properties of the fluid, which means that some substance other than the one naturally present must be employed.